The present invention relates to a light emitting device using the light emitting diode (LED) and the method for manufacturing the device.
The LED is made by forming a pn junction on a semiconductor wafer consisting of a compound of the III-V family such as GaP, GaAs and the like.
Experiments have been carried out to obtain a light emitting device which emits desired colors. The light emitting device has a sealing resin such as epoxy resin and silicon resin. In order to generate a desired color, fluorescence materials are mixed in sealing resin.
However, since the fluorescence material is heavy compared with the sealing resin, particles of the fluorescence material deposit in the resin before hardening of the resin. The deposited particles disperse irregularly on the LED and the substrate. Consequently, the light emitted by the light emitting device is irregular in color and luminance distribution.
On the other hand, there has been provided a method for manufacturing a plurality of light emitting devices by using dies. However, the die method is complicated because of a number of process steps.
An object of the present invention is to provide a light emitting device having uniform color and luminance distribution.
Another object of the present invention is to provide a method which is able to manufacture a light emitting device at few steps.
According to the present invention, there is provided a light emitting device comprising a substrate, an LED mounted on the substrate, a first transparent layer sealing the LED, a second transparent layer provided around the first transparent layer, fluorescent material being included in either of the first transparent layer and the second transparent layer, and a reflector layer formed on outside walls except an upper side.
A coloring agent is included in either of the first and second transparent layers.
Fluorescent material and a coloring agent are included in either of the first and second transparent layers.
The second transparent layer has an inverted trapezoid shape in section.
A method for manufacturing a light emitting device, comprising the steps of preparing a substrate aggregation having a plurality of substrate divisions, mounting an LED on the substrate division, forming a first transparent layer on the substrate aggregation, cutting off the first transparent layer at division lines surrounding the substrate division to form an individual first transparent layer, forming a second transparent layer on the individual first transparent layer, cutting off the second transparent layer at division lines surrounding the substrate division to form an individual second transparent layer, forming a reflector film on outside walls of the individual second transparent layer, and dividing the substrate division at division lines of the division.
The method further comprises providing a substrate attachment between adjacent substrate divisions, and cutting off the substrate attachment and the second transparent layer in an inverted V-shape in section.
These and other objects and features of the present invention will become more apparent from the following detailed description with reference to the accompanying drawings.